From Whakapapa via Glacier Knob

This is the most popular way to access the Summit Plateau and Crater Lake. Until well into summer, most years, snow blankets the upper mountain. But by autumn the steaming Crater Lake is ringed by stark burnt-orange rocks and dark, ash-covered snowﬁelds – dramatic evidence that the volcano is a restless environment, a place not quite of this world. Although one-way lift tickets up the skiﬁeld are available in winter, and during the summer holiday period, ﬁrst-time visitors may want to walk, if only to gain a better idea of the topography of the mountain: it is not that straightforward.
In summer, guided walks begin from the top of the skiﬁeld chairlifts, up a scoria track to the Crater Lake. In winter, the short climb to the Summit Plateau from the Whakapapa skiﬁeld is many North Islanders’ ﬁrst true alpine experience.
From the carpark you can reach the vicinity of the NZAC Ruapehu Hut in about 90 minutes. Follow Tennents Valley to Hut Flat, and then a poled route climbs up Egmont Ridge behind (west of) the Ruapehu Ski Club lodges onto the western side of Delta Ridge. The hut is on the brow of this ridge at 2040m elevation (grid ref 310138). From here there are two main routes. Note that parts of both routes lie in paths followed by lahars on the three occasions they have been recorded on this side of the mountain. Two of these, in 1969 and 1975, occurred in ‘blue sky’ eruptions.
From Delta Corner (the rocky end of Delta Ridge) it’s about another 90 minutes to Glacier Knob. Climb up ‘The Gut’ – a popular ski gully between Knoll Ridge and Restful Ridge – and continue beyond straight up the broad valley to the obvious knob on the skyline. Alternatively, just before the top sidle up and slightly to the climber’s left (east) to reach The Notch. This gives direct access to the Summit Plateau. In winter, watch for snow loading from the westerly quarter. From Glacier Knob it’s worth going south along the ridge to The Dome at 2672m. Here you overlook Crater Lake, and beyond is Tahurangi, the true summit of Ruapehu. Dome Shelter is a small emergency shelter, not intended for overnight use, on top of The Dome at grid ref 313113. During winter the door is often buried by snow and ice, so there is a hatch in the roof for emergency access. This shelter will be removed ‘when it falls due for replacement’. Check with DoC on its current status.